Hello, I want to ask IF I can use distoima to undistord some photos of building with a slightly rounded border due to cameras large angles.  
 
I first load the pictures in IM, calibrate the cameras, then I take note of the focal length and the distortion level for each picture... then I undistord them with distoima, then I will reload those undistorded pictures in IM, and restart fresh from here. (much easier to draw nice straight primitives over the buildings for exemple, better matching for the corners and lines of windows, etc...)
 
I have not tried yet to reload in IM those new undistorded pictures, but I accomplished the first step, and it makes buildings straight like justice... very cool...
 
Little question is... when I have a negative number in Ditortion parameter in IM,  do I write "d" for distord instead of "u" for undistord (in distoima), and if I have to use "d", should I keep the negative sign in front of the number ? stupid question ?  
 
Thanks to let me know if you have the answer..
Hervé

Hello,
 
In IM once shots are calibrated, the images are drawn undistorted in the 3dview, and rounded borders should become straight. If I remember the images are tiled and the distortion is applied to each tile globally, so its an approximation of the undistorted image, but it should do the work.
 
I let Dominique answer about distoima and the parameters.
 
One other thing is (may be Dominique knows also) that if you use distoima, the resulting images may be cropped and have a different size than the original images.  
 
The good thing of this process is that you get undistorted cameras, that you can easily export to other 3D packages (they usually don't support distortion)
 
 
Stef

Well, I am not sure... but in the views (calibrated cameras), buildings are still a bit deformed (rounded), and if I use distoima with the numbers I find in each image (Focal lenght & distortion) then and only then the image become complete undistorded.... I am going to post in the gallery section my results, with a screen capture of IM with the calibrated cameras, and on the other the same image (cameras view) with distoima applied with the numbers I have found in IM.... BTW, it does not seems to do any crop... same size... at least on my test....
 
Later, Hervé
 
also If you want to use the photos in a comp package you HAVE to undistord them before.... coz IM does not output any undistord images, except the txtures... no ?

and the corrected in Ditoima using the numbers in calibrated Cameras in IM

Hello Herve,
 
  Yes, for sure distoima does a better work than the IM 3D view.
In IM 3dview we use an approx process as said before, to keep good drawing performance.  
But at texture extraction step, we undistort at pixel level (like distoima).
 
Have you tried to recalibrate such undistorted shots ?
 
Stef

I guess you're right Stef, adding 12 more markers and 5 right angles helped a bit, but no miracles... it still does not the same good job as distoima... and it's strange coz I use the numbers privided BY Image Modeler.... anyway, I guess it'll be good enough... also it does not show on all photos, some are undistorded better than some others...
 
Cheers, Later, Hervé

xcuse.... read "provided" not privited"....